A "Twitter troll" has been ordered not to contact Coldplay singer Chris Martin and Countdown presenter Rachel Riley after sending hundreds of abusive tweets, the Crown Prosecution Service said.

Anthony Wells from Chelmsford in Essex admitted harassing Riley with violent and distressing messages on Twitter for around seven months, including sending her death threats.

Following his admission a second charge of similar harassment against musician Martin was subsequently not pursued, the CPS said.

Wells was yesterday sentenced to a hospital order under the Mental Health Act, and a restraining order against the two celebrities was imposed for five years.

East of England Crown Prosecutor Punam Malhan said: "Mr Martin indicated that a plea to the charge involving Ms Riley would be acceptable to ensure that Mr Wells gets the medical help he needs and that he was content for us to not to proceed in relation to the remaining charge.

"Taking Mr Martin's view into account we decided it was no longer in the public interest to continue with the second charge of harassment and that charge was today left on file."

He added: "Everyone should be able to go about their daily lives free from harassment caused by someone deliberately making offensive, violent messages about them on social media.

"We take allegations of this kind very seriously and especially where there is evidence of a course of conduct which causes fear or distress to someone, regardless of whether a victim is in the public eye or not."